1. Field of the Invention
The present invention relates to an imaging apparatus as typified by a digital camera, and more particularly to an imaging apparatus characterized by its heat dissipation structure for cooling an image sensor.
2. Description of the Related Art
In recent years, imaging apparatuses using a solid-state image sensor, such as a charge coupled device (CCD) or complementary metal oxide semiconductor (CMOS), to convert an object image into an electric signal have become widespread. The solid-state image sensor generally includes semiconductors, thermal noise is generated in the image sensor. Moreover, elements mounted around the solid-state image sensor are affected by the generated head.
Because the thermal noise (also referred to as dark noise) increases monotonically with a rise in temperature of the image sensor, it is desirable to keep temperature of the image sensor at the lowest possible to reduce generation of the thermal noise and to capture an image with high image quality.
Therefore, some imaging apparatuses used for high-speed continuous shooting and for long exposure imaging in astrophotography are provided with a cooling mechanism for an image sensor to obtain images with high image quality.
Meanwhile, downsizing of digital cameras has been strongly demanded, and miniaturization of a camera body, as exemplified by downsizing and high density integration of an optical system and circuit elements, is steadily advanced while maintaining high functionality and performance.
However, the conventional cooling mechanism generally has a complicated structure which is one factor that makes miniaturization of digital cameras difficult.
To solve the above problem, Japanese Patent Application Laid Open No. 2003-304420 discusses a mechanism which has an elastic heat-conductive member disposed between an imaging plate and a display unit to dissipate heat.
When the image sensor is mounted on a lens barrel, if the image sensor, such as a CCD or CMOS sensor, is tilted, a problem arises in optical performance such that an image is in focus in some areas but out of focus in other areas around an optical axis.
Therefore, as shown in FIG. 8, an optical adjusting mechanism is provided to adjust the tilt or a position of an imaging plate 4′ supported by urging springs 3′ by tightening or loosening adjusting screws 2′.
At this time, if a stress of the heat-conductive member 5′ is large, this stress hampers the correction of the tilt of the imaging plate 4′ (more specifically, a stress in a “B” direction applied by the heat-conductive member 5′ reduces urging effects of the urging springs 3′ which applies a stress in an “A” direction.)
The present invention is directed to an imaging apparatus which can prevent a temperature rise in an image sensor and form a high quality image data showing less noise even in high-speed continuous shooting and long-time continuous exposure imaging without detracting from performance of a tilt adjusting mechanism.